In the processing of impure molybdenum trioxide to pure molybdenum compounds, ammonium dimolybdate leaves spent liquors which contain molybdenum and potassium as an impurity. As a result of this processing, the molybdenum recovered therefrom is high in potassium. Also this spent liquor contains ammonia which would be a problem to store. Another disadvantage of having this spent liquor is the tie up of space, equipment and molybdenum in storing it and this resulting in less efficient throughput.
Therefore, a process in which this spent liquor could be constructively used in recovery of molybdenum would be highly desirable.